An Iranian man jumps over a bonfire during Chaharshanbe Souri, or Wednesday Feast, an ancient Festival of Fire, on the eve of the last Wednesday of the solar Persian year, in Tehran, Iran, Tuesday, March 17, 2015. In Tehran, people light bonfires, set off fireworks and send wish lanterns into the night sky as part of an annual ritual that dates back to at least 1700 B.C. and is linked to Zoroastrianism. Since the 1979 Islamic Revolution, hard-liners have discouraged the celebration, viewing it as a pagan holdover from pre-Islamic times. (AP Photo/Vahid Salemi)
(The Associated Press)

Iranians watch a firework display during Chaharshanbe Souri, or Wednesday Feast, an ancient Festival of Fire, on the eve of the last Wednesday of the solar Persian year, in Tehran, Iran, Tuesday, March 17, 2015. In Tehran, people lit bonfires in public places, set off fireworks and sent wish lanterns floating into the night sky as part of the annual ritual that dates back to at least 1700 B.C. and is linked to Zoroastrianism. Since the 1979 Islamic Revolution, hard-liners have discouraged the celebration, viewing it as a pagan holdover from pre-Islamic times. (AP Photo/Vahid Salemi)
(The Associated Press)

An man holds up a firework during Chaharshanbe Souri, or Wednesday Feast, an ancient Festival of Fire, on the eve of the last Wednesday of the solar Persian year, in Tehran, Iran, Tuesday, March 17, 2015. In Tehran, people light bonfires, set off fireworks and send wish lanterns into the night sky as part of an annual ritual that dates back to at least 1700 B.C. and is linked to Zoroastrianism. Since the 1979 Islamic Revolution, hard-liners have discouraged the celebration, viewing it as a pagan holdover from pre-Islamic times. (AP Photo/Vahid Salemi)
(The Associated Press)

In Tehran, people lit bonfires in public places, set off fireworks and sent wish lanterns floating into the night sky as part of an annual ritual that dates back to at least 1700 B.C. and is linked to Zoroastrianism.

Since the 1979 Islamic Revolution, hard-liners have discouraged the celebration, viewing it as a pagan holdover from pre-Islamic times. Police warned revelers to avoid major streets and squares but have not moved to disperse them.

The holiday comes ahead of Nowruz, the Persian new year, which will be celebrated on March 21.